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981.
α-Fetoprotein (AFP) is a prospective biopharmaceutical candidate currently undergoing advanced-stage clinical trials for autoimmune indications. The high AFP expression yields in the form of inclusion bodies in Escherichia coli renders the inclusion body route potentially advantageous for process scale commercial manufacture, if high-throughput refolding can be achieved. This study reports the successful development of an ‘anion-exchange chromatography’-based refolding process for recombinant human AFP (rhAFP), which carries the challenges of contaminant spectrum and molecule complexity. rhAFP was readily refolded on-column at rhAFP concentrations unachievable with dilution refolding due to viscosity and solubility constraints. DEAE-FF functioned as a refolding enhancer to achieve rhAFP refolding yield of 28% and product purity of 95% in 3 h, at 1 mg/ml protein refolding concentration. Optimization of both refolding and chromatography column operation parameters (i.e. resin chemistry, column geometry, redox potential and feed conditioning) significantly improved rhAFP refolding efficiency. Compared to dilution refolding, on-column rhAFP refolding productivity was 9-fold higher, while that of off-column refolding was more than an order of magnitude higher. Successful demonstration that a simple anion-exchange column can, in a single step, readily refold and purify semi-crude rhAFP comprising 16 disulfide bonds, will certainly extend the application of column refolding to a myriad of complex industrial inclusion body proteins. 相似文献
982.
James空间的推广 总被引:1,自引:0,他引:1
R.H.Lohman和P.G.Casazza[2]就自反的、具有对称的块P——Hilbert基的Banach空间进行了讨论,给出了一阶次自反Banach空间的一种构造方法。本文在一类具有IS型基的Banach空间上进行了推广,并给出了构造一阶次自反空间的更一般性的方法。 以下记号S、的意义同[2],文中IS序列、ESA序列、SA序列及单调基、正规基的定义可见[2]、[3]。并总设E是Banach空间,{x_i}是E之IS型单调正规基。 一般的James空间定义类似[2],区别在于对于a=(a_i)∈S和我们定义: 相似文献
983.
Scanning tunnelling microscopy is used to analyse the structure of the columnar metallomesogen bis[1-(3',4',5'-trioctyloxyphenyl)-3-(4'-octyloxphenyl)prop [Pd(II)BPOC8], on the basal plane of highly oriented pyrolytic graphite. It is observed with near molecular level resolution that adsorbed molecules form a regular two-dimensional (2D) arrangement on the surface. The intermolecular spacing in the 2D crystallization is significantly shorter than in the intercolumnar mesophase, indicating that the alkyl chains of adjacent molecules interdigitate. Change in the carbon length of alkyl side chain groups results in a change in molecular periodicity in the 2D crystal. Models for the unit cell are proposed based on computer simulation. 相似文献
984.
Houqin Su Xuncheng Huang Xuncheng Huang Xiaoning Xu 《Journal of mathematical chemistry》2008,43(3):1273-1284
A three-dimensional bio-reactor model of exploitative competition of two predator organisms with inhibition responses for
the same renewable organism with reproductive properties is considered. By constructing a modified Lyapunov function and using
LaSalle’s invariant principle, it is shown that the lower “break-even” concentration predator organism survives in the competition.
相似文献
985.
986.
Ding-Shan Ruan Ya-Li Li Lei Wang Dong Su Feng Hou 《Journal of Sol-Gel Science and Technology》2010,56(2):184-190
Spinnable solutions are obtained in the sol–gel system of tetraethoxide (TEOS, Si(OC2H5)4) and vinyltrimethoxysilane (VTMS, CH2=CHSi(OCH3)3) under aqueous condition (water) with acid catalysts (HNO3 and HCl). Polysiloxane (PSO) fibers are drawn from the solution and characterized by spectroscopic and structural analyses.
29Si-nuclear magnetic resonance NMR) spectral analysis of the PSO fiber indicates the incorporation of atomic carbon in the
silica network. 13C-NMR analysis shows the existence of considerable amount of hydroxyl groups in the PSO fiber. The spinnablity of the solution
is studied by varying the mole ratios of the alkoxides, solvents and catalysts as well as precursor chemistries. The amount
of water and catalysts are found to be important for the attaining of a spinnable state in the solution. SiOC fibers are obtained
after pyrolysis of the PSO fibers with a high ceramic yield (88 wt%). The high ceramic yield attributes to the incorporation
of vinyl-groups in the gel fiber that enhances crosslinking during pyrolysis. The SiOC fiber has a tensile strength of 776 MPa
and electrical conductivity of 3.6 × 10−4 S/m. 相似文献
987.
Weiwei Su Yiming Chen 《Communications in Nonlinear Science & Numerical Simulation》2009,14(5):2293-2300
In this paper, the global exponential stability is investigated for a class of stochastic interval neural networks with time-varying delays. The parameter uncertainties are assumed to be bounded in given compact sets. Based on Lyapunov stable theory and stochastic analysis approaches, the delay-dependent criteria are derived to ensure the global, robust, exponential stability of the addressed system in the mean square. The criteria can be checked easily by the LMI control toolbox in Matlab. A numerical example is given to illustrate the effectiveness and improvement over some existing results. 相似文献
988.
989.
L J Shi Z M Ni S F Lu G Wang H L Qi Q X Su 《Science in China. Series B, Chemistry, life sciences & earth sciences》1989,32(7):816-821
Spindle fiber attachments (SFAs) were enriched in a fraction of nuclei isolated from mouse livers. The enrichment method combines sonication, treatment with 2 mol/L NaCl and high speed centrifugation. SFA was enriched 27-fold on the average (n = 4) when measured by radioimmunoassay. The basic method offers opportunities for further increases of yield and for the enrichment of SFA of other vertebrates. 相似文献
990.